Means and constructions for slidably maintaining fasteners within a workpiece are well-known, as is evident, for example, from the following patents:
______________________________________ Webster 1,369,995 03/01/21 Anderson 1,927,780 09/19/33 Sitzler 2,010,569 08/06/35 Currier, et al. 3,209,806 10/05/65 Tildesley 3,727,254 04/17/73 Menke 4,396,327 08/02/83 Jonsson 4,655,656 04/07/87 ______________________________________
These patents disclose generally the use of wings upon the shank of the fastener so as to retain it within its respective workpiece. Additionally, the patent of Ryner, U.S. Pat. No. 3,209,807, discloses an apparatus and a means for positively retaining a screw within a hole defined within a sheet of metal. The apparatus consists of a screw having a conical recess defined within a bottom end of the head and a bushing composed of a relatively soft metal. The bushing is inserted into the hole from a side opposite to the screw, and extends beyond the surface of the sheet towards the screw. As the screw is inserted into the bushing, the conical recess deforms a portion of the bushing, thereby retaining the screw. This means, however, is quite time consuming and labor intensive because an operator must be present upon both sides of the sheet so as to retain the screw properly.
Other costly and labor intensive means are evident in the patent of Acres, U.S. Pat. No. 2,987,811, and the patent of Gulistan, U.S. Pat. No. 4,655,658. Both of the means disclosed in these patents require the use of a tool to affect the captivation of the screw within an aperture defined within a workpiece.
The patent of Seely, U.S. Pat. No. 4,032,806, discloses another means for retaining screws. This means causes the threads upon the screw to cut through an aperture having a diameter substantially smaller than the corresponding diameter of the screw. This means may cause damage to the threads, and lead to an unsatisfactory, and possibly unsafe connection formed by means of the threaded components.
The patent of Hill, U.S. Pat. No. 4,557,653, discloses a snap-fit means for captivating a panel screw. While this means is relatively inexpensive, it is limited to application with a nonmetallic screw. While the nonmetallic composition of the screw may be of little consequence in some environments, it is critical in others, such as for example, attaching a manifold to an engine, and other environments which experience high temperatures or great stresses.
The patents of Wagner, U.S. Pat. No. 4,732,519 and 4,975,008, disclose further means for retaining a fastener within an aperture defined within a workpiece. In accordance with these means, wings protrude from the shank of the fastener which is inserted into an aperture having a sleeve associated therewith. In order to retain the fastener within the aperture, a rubber grommet and/or a washer are placed over the sleeve, thereby reducing the diameter defined thereby. These means are also time consuming and quite labor intensive, due to the above-discussed characteristics.